• Economic and Environmental Geology
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• v.51 no.2
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• pp.87-97
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• 2018

The cesium (Cs) removal from the contaminated water system has been considered to be difficult because the cesium likes to exist as soluble phases such as ion and complexes than the solid in water system. Many researches have focused on developing the breakthrough adsorbent to increase the cesium removal efficiency in water. In this study, the laboratory scale experiments were performed to investigate the feasibility of the adsorption process using the bamboo charcoal for the Cs contaminated water system. The Cs removal efficiency of the bamboo charcoal were measured and the optimal adsorption conditions were determined by the adsorption batch experiments. Total 5 types of commercialized bamboo charcoals in Korea were used to identify their surface properties from SEM-EDS and XRD analyses and 3 types of bamboo charcoals having large specific surface areas were used for the adsorption batch experiment. The batch experiments to calculate the Cs removal efficiency were performed at conditions of various Cs concentration (0.01 - 10 mg/L), pH (3 - 11), temperature ($5-30^{\circ}C$), and adsorption time (10 - 120 min.). Experimental results were fitted to the Langmuir adsorption isotherm curve and their adsorption constants were determined to understand the adsorption properties of bamboo charcoal for Cs contaminated water system. From results of SEM-EDS analyses, the surfaces of bamboo charcoal particles were composed of typical fiber structures having various pores and dense lamella structures in supporting major adsorption spaces for Cs. From results of adsorption batch experiments, the Cs-133 removal efficiency of C type bamboo charcoal was the highest among those of 3 bamboo charcoal types and it was higher than 75 % (maximum of 82 %) even when the initial Cs concentration in water was lower than 1.0 mg/L, suggesting that the adsorption process using the bamboo charcoal has a great potential to remove Cs from the genuine Cs contaminated water, of which Cs concentration is low (< 1.0 mg/L) in general. The high Cs removal efficiency of bamboo charcoal was maintained in a relatively wide range of temperatures and pHs, supporting that the usage of the bamboo charcoal is feasible for various types of water. Experimental results were similar to the Langmuir adsorption model and the maximum amount of Cs adsorption (qm:mg/g) was 63.4 mg/g, which was higher than those of commercialized adsorbents used in previous studies. The surface coverage (${\theta}$) of bamboo charcoal was also maintained in low when the Cs concentration in water was < 1.0 mg/L, investigating that the Cs contaminated water can be remediated up with a small amount of bamboo charcoal.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.2
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• pp.135-145
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• 2011

Purpose: This study was conducted to investigate the actual condition of caring soft contact lens cases and the change in contamination level of lens cases by wearing and storage period of soft contact lens. Methods: The actual condition of caring soft lens cases was surveyed with sixty-three of contact lens wearers. Soft contact lenses were worn for 1, 3, 7 and 14 days, and the lenses were separately stored in 12 lens cases for 1, 3 and 7 days. The contamination level of lens cases was determined by counting the numbers of microorganisms, gram negative bacteria and fungi. Results: Only 14% of survey answerers cleaned their lens cases with a brush, rinsed and dried them upside down before next usage of lens case when those lenses were kept for a long time. Furthermore, 54% of total answerers just kept soft contact lens in the case without changing the multipurpose solution. Microorganisms, gram negative bacteria and fungi were detected in lens cases even when soft contact lens were kept for 1 day in the lens case after wearing for 1 day and cleaning it with multipurpose solution. The numbers of microorganisms, gram negative bacteria and fungi in lens cases increased with storage periods of soft contact lens, and also contamination level of lens cases was increased in accordance with wearing period of lens. In the lens cases without changing multipurpose solution, the numbers of microorganisms, gram negative bacteria and fungi increased with storage period of lens with statistical significance. Conclusions: This study showed that lens wearers' concerns on caring contact lens case were not satisfactory. As the result, the contamination of lens cases was related to increase of lens wearing and storage periods suggesting that the proper instruction and education for lens wearers are required.

• Proceedings of the Korean DIstribution Association Conference
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• 2006.08a
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• pp.47-68
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• 2006

This study aims to determine the association structure of the behavioral relationship variables, such as trust, commitment, cooperation, communication and coercive power, in the relationship between the buyers and suppliers of industrial parts. It also investigates the impact of the use of IT technologies on the relationships quality. Data was collected from 216 part suppliers of machinery, electronics and automobiles located in Incheon. Data supported all of the proposed hypotheses. First, it was confirmed that parts suppliers' trust in buyers leads to the commitment into relationships with buyers. Second, cooperation and communication showed a positive influence on parts suppliers' trust in buyers, and coercive power gave a negative influence on trust. Third, the use of IT technologies like Internet and E-Mail between parts suppliers and buyers was verified to have generally a positive influence on the quality of relationships. At the same time, cooperation and communication were confirmed to have a positive influence on each other, and cooperation and coercive power as well as communication and coercive power were confirmed to have negative influence on each other. This study is a pioneering attempt to examine the relationships between suppliers and buyers of industrial parts, and the influence IT technologies on the relationship quality. Also, the findings will be practically much helpful to find how to reinforce the relationships between parts suppliers and buyers.

• Clinical and Experimental Pediatrics
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• v.48 no.10
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• pp.1068-1075
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• 2005

Purpose : The role of ghrelin, which promotes the secretion of growth hormone, was not well known until now. Recently it was found that the mutation of ghrelin gene is related to obesity and diabetes. This study is to find the screening method that can easily and effectively detect the polymorphism of Leu72Met in ghrelin gene of obesity patients and apply it to clinical usage. Methods : We compared PCR-RFLP, PCR-SSCP and ARMS methodologies for analyzing of the polymorphism of Leu72Met in ghrelin gene of obesity children, and also studied the merits and demerits of these methodologies. Results : In this study, we were able to find out the band of peculiar allele of Leu72Met in ghrelin gene using PCR-RFLP, PCR-SSCP and ARMS analyses. The polymorphism of Leu72Met in ghrelin gene determined by all above methodologies was in complete agreement. Compared to the PCR-RFLP and PCR-SSCP, ARMS analysis is simple, inexpensive and also consume less time. It is very sensitive to analyze the polymorphism and easy to understand the results of test. Conclusion : Though PCR-RFLP, PCR-SSCP and ARMS analyses were sensitive to analyze the polymorphism of Leu72Met in ghrelin gene, ARMS analysis appears to be more efficient than PCR-RFLP and PCR-SSCP. Therefore, we conclude that ARMS analysis is suitable to analyze the polymorphism of Leu72Met in ghrelin gene for large quantity of specimens.

• Journal of Navigation and Port Research
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• v.28 no.10 s.96
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• pp.899-908
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• 2004

The rise of income and introduction of 5 day a week working system give korean people opportunities to enjoy their leisure time. And many korean people have much interest in oceanic sports such as yachting and also oceanic leisure equipments. With the popularization and development of the equipments, the scope of oceanic activities has been expanding in Korea just as in the advanced oceanic countries. However, The current conditions for the sports in Korea are not advanced and even worse than underdeveloped countries. In order to develop the underdeveloped resources of Korean marina, we need to customize the marina models of advanced nations to serve the specific needs and circumstances of Korea As such we have carried out a comparative analysis of how Austrailia, Newzealand, Singapore, japan and Malaysia operate their marina, reaching the following conclusions. Firstly, in marina operations, in order to protect personal property rights and to preserve the environment, we must operate membership and non-membership, profit and non-profit schemes separately, yet without regulating the dress code entering or leaving the club house. Secondly, in order to accumulate greater value added, new sporting events should be hosted each year. There is also the need for an active use of volunteers, the generation of greater interest in yacht tourism, and the simplification of CIQ procedures for foreign yachts as well as the provision of language services. Thirdly, a permanent yacht school should be established, and classes should be taught by qualified instructors. Beginners, intermediary, and advanced learner classes should be managed separately with special emphasis on the dinghy yacht program for children. Fourthly, arrival and departure at the moorings must be regulated autonomically, and there must be systematic measures for the marina to be able, in part, to compensate for loss and damages to equipment, security and surveillance after usage fees have been paid for. Fifthly, marine safety personnel must be formed in accordance with Korea's current circumstances from civilian organizations in order to be used actively in benchmarking, rescue operations, and oceanic searches at times of disaster at sea.

• Journal of Radiation Protection and Research
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• v.40 no.3
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• pp.124-131
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• 2015

Radiation exposure to humans can be caused by the gamma rays emitted from natural radioactive elements(such as uranium, thorium and potassium and any of their decay products) of Naturally Occurring Radioactive Materials(NORM) or Technologically Enhanced Naturally Occurring Radioactive Materials(TENORM) added consumer products. In this study, assume that activity of radioactive elements is $^{238}U$, $^{235}U$, $^{232}Th$ $1Bq{\cdot}g^{-1}$, $^{40}K$ $10Bq{\cdot}g^{-1}$ and the gamma rays emitted from these natural radioactive elements radioactive equilibrium state. In this study, reflected End-User circumstances and evaluated annual exposure dose for products based on ICRP reference voxel phantoms and ICRP Recommendation 103 using the Monte Carlo Method. The consumer products classified according to the adhere to the skin(bracelet, necklace, belt-wrist, belt-ankle, belt-knee, moxa stone) or not(gypsum board, anion wallpaper, anion paint), and Geometric Modeling was reflected in Republic of Korea "Residential Living Trend-distributions and Design Guidelines For Common Types of Household.", was designed the Room model($3m{\times}4m{\times}2.8m$, a closed room, conservatively) and the ICRP reference phantom's 3D segmentation and modeling. The end-user's usage time assume that "Development and Application of Korean Exposure Factors." or conservatively 24 hours; in case of unknown. In this study, the results of the effective dose were 0.00003 ~ 0.47636 mSv per year and were confirmed the meaning of necessary for geometric modeling to ICRP reference phantoms through the equivalent dose rate of belt products.

• Journal of Bio-Environment Control
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• v.25 no.4
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• pp.225-231
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• 2016

Glasshouse heating package technologies to improve energy usage efficiency in winter were developed. Heating package was composed of the ground water source heat pump with heating capacity of 105kW, the aluminum multi-layer thermal curtain with six layers of different materials and the root zone local heater with XL pipes of ${\phi}20mm$. Venlo type glasshouse($461m^2$) with the heating package was compared with the same type and area control glasshouse with the light oil boiler, the usual non-woven fabric thermal curtain with respect to the glasshouse inside temperature, relative humidity, crop growth, and heating energy consumption. The results of test in paprika cultivation glasshouses showed that the air temperature inside glasshouse with aluminum multi-layer thermal curtain was maintained $2.2^{\circ}C$ higher than that of control glasshouse in un-heating night time and the temperature in bed with root zone local heating was $4.7^{\circ}C$ higher than that in bed without local heating. Average heating coefficient of performance(COP) of the ground water source heat pump used in paprika cultivation was 3.7 and the glasshouse inside temperature was maintained at $21^{\circ}C$ of heating set up temperature. The heating energy consumptions per 10a were measured at 14,071L of light oil and 364kWh of electric power for the control glasshouse and 35,082kWh for the glasshouse applied heating package. As results, the heating cost of the glasshouse applied heating package was 87 percent lower than that of control glasshouse. The growths of paprika in glasshouses of control and applied heating package did not show any significant difference.

• Journal of the Korean Society of Radiology
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• v.8 no.7
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• pp.467-477
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• 2014

The purpose of this study is to offer data base for establishment of dental training x-ray generator based safety usage through surveying real radiation safety management state of radiation worker's in plan of operations that have dental training x-ray generators and use it. For it, comprehensive references were surveyed referring reports of current state of regulation technique development and domestic radiation safety evaluation and nuclear related legislation regarding radiation safety management of dental training x-ray generators. On the basis of it, questionnaires were filled in about respondent's general characteristic radiation safety manager's status current state of radiation safety management and the level of knowledge & consciousness. For the study, the survey was conducted to 224 people of radiation safety managers and university graduates training assistants and full-time professors who can treat dental training x-ray generators in education center. through this survey 95 questionnaires were used as analysis materials except the insufficient and omitted responses. As a method of analysis, the frequency and percentage were figured out with the general characteristics and safety manager's status. Chi-square test for frequency and correlation per question analysis and Pearson correlation analysis for crosslevel correlation were done with current state of radiation safety management and knowledge & consciousness level. As a result, running dental training x-ray generators was dealt with by 20's to 40's who have high education level over post undergraduate degree and major in dental hygienic. In addition, female have higher consciousness level for radiation safety management than male. It shows significal linear relation statistically(${\chi}^2$ >5, 0.1${\chi}^2$ >5, 0.3${\chi}^2$ >5, 0.3

• Economic and Environmental Geology
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• v.40 no.2 s.183
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• pp.209-221
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• 2007

Numerical analysis was performed to investigate the effect of heavy metal contamination on neighboring environment in case a dam is constructed by using rockfill materials contaminated by heavy metals. The numerical simulation carried out in this research includes both subsurface flow and contaminant transport in the inside of the CFRD(Concrete Faced Rockfill Dam), using two commercial programs, SEEP2D and FEMWATER. The three representative cases of scenarios were chosen to consider a variety of cases occurring in a dam site; (1) Scenario 1 : no crack in the concrete face slab, (2) Scenario 2 : a crack In the upper part of face slab, and (3) Scenario 3 : a crack between plinth and face slab in the lower part of face slab. As a result of seepage analysis, the amount of seepage in scenario 2 was calculated as $14.31\sim14.924m^3/day$ per unit width, corresponding to the 1,000 times higher value than that in other scenarios. Also, in the simulation of contaminant transport by using FEMWATER, specified contaminant concentration of 13 ppb in main rockfill zone was set to consider continuous leakage from the rock materials. Through the analysis of contaminant transport, we found that elapsed times to take for the contaminant concentration of about 2 ppb to arrive at the end of a dam are as follows. Scenario 1 has the elapsed time of 55,000 years. In Scenario 2. it is 50 years. Finally, scenario 3 has 27,000 years. The rapid transport of the contaminant in scenario 2 was attributed to greater seepage flow by 500 times than other scenarios. Although, in case of upper crack in the face slab, it was identified that the contaminant might transport to the end of a dam within 100 years with about 2 ppb concentration, however, it happened that the contaminant was hardly transported out of the dam in other scenarios, which correspond to either no crack or a crack between plinth and face slab. In conclusion, the numerical analysis showed that the alternative usage of the contaminated sand and gravel as the dam embankment material can be one of the feasible methods with the assumption that the cracks in a face slab could be controlled adequately.

• Journal of Environmental Impact Assessment
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• v.29 no.2
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• pp.79-92
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• 2020

This study aimed at analyzing the current status and further needs of ecological information which is provided with the civil servants in the process of climate change adaptation planning in ecosystem sector and at providing suggestions for future development of ecological knowledge on climate change. Therefore, we conducted a questionary survey titled as "the knowledge-base and information needs for climate change adaptation in ecosystem sector" with the civil servants who are engaged with adaptation practices in the ecology related divisions in 17 regional local governments (RLG) and the affiliated basic local governments (BLG) in Korea. As a result, the characteristics of ecological information which is applied in public practices was analyzed and strategies for improved utilization was suggested. 75% of the respondents (RLG 85% and BLG 72%) were aware of the relativeness between the existence and utilization of ecological information and the execution of climate adaptation practices in ecosystem sector. They were agreed with the necessity of ecological information not only in adaptation practices but also overall affairs in the ecological related division in the local government (RLG 82% and BLG 72%). The current situation of utilizing ecological information which is produced from central orlocal government to civil affairs were only represented as 64 persons (28%) in RLG and 42 persons (18%) in BLG. One of the major obstacles that the respondents confront with when applying ecological information to public practices was deficit of prior knowledge on the ecological information itself, such as awareness of the characteristics of ecological information and the link with public affairs for adaptation plans. Therefore, delivering current knowledge and ecological information on climate change by educational and promotional method is an urgent priority to the civil servant. The future needs on ecological information for local government servants were deduced as basic information on local ecosystem and applied knowledge on local development to meet the biodiversity conservation and ecosystem services at the same time. The respondents expected not only the specific guidelines for using ecological information to apply on the adaptation plans in the relevant divisions of the local governments but also the institution where the usage activation of ecological information would be operated and managed to enhance the information utilizing structure in the local government. In the nation-wide, the capacity of local governments should be enhanced with adaptation knowledge and the application of appropriate information to the public practices by central government's aiding with the better quality of information, its public promotion, and the applicability to civil affairs.